FAQs – Travelling at High Altitude

1. Why is it so difficult to breath at high altitudes?

When we breathe in air at sea level, the atmospheric pressure of about 14.7 pounds per square inch (1.04 kg. per cm.2) causes oxygen to easily pass through selectively permeable lung membranes into the blood. At high altitudes, the lower air pressure makes it more difficult for oxygen to enter our vascular systems.
More at Human Biological Adaptability: Adapting to High Altitude

2. What is altitude sickness?

Altitude sickness is a common condition that can occur when you climb to a high altitude too quickly. The decrease in atmospheric pressure makes breathing difficult because you aren’t able to take in as much oxygen. Most cases are mild, with symptoms that can include: headache. nausea.
More at Altitude sickness – NHS Choices
The effects of high altitude on humans are considerable. The percentage oxygen saturation of hemoglobin determines the content of oxygen in blood. After the human body reaches around 2,100 m (7,000 feet) above sea level, the saturation of oxyhemoglobin begins to plummet.
More at Effects of high altitude on humans – Wikipedia

3. How long does it take to get altitude sickness?

Most people with altitude sickness feel normal in 2 or 3 days. In severe cases, when someone has made a sudden climb to over 10,000 ft and has overexerted himself, there can be life-threatening complications. These complications include pulmonary edema (lung failure) or cerebral edema (swelling of the brain). However, it depends on your body type. Even the fittest person could get altitude sickness.
More at What causes altitude sickness?

4. What you should do for altitude sickness?

• Acclimatize and take it easy. Spend your first day at high altitudes relaxing.
• Climb high, sleep low. Walk very slow while going up, esp. if you are trekking.
• Do not smoke and avoid drinking alcohol.
• Drink extra water and fluids – soups, tea etc. Keep the body hydrated. Very important.
• Eat foods that are high in carbohydrates.
• Get headache relief.
• Don’t go up until symptoms go down.
• If the symptoms get worse, get artificial oxygen immediately and go to lower altitudes immediately.
More at Altitude Sickness Remedies – Travel Health – HealthCommunities.com

During acclimatization over a few days to weeks, the body produces more red blood cells to counteract the lower oxygen saturation in blood in high altitudes. Full adaptation to high altitude is achieved when the increase of red blood cells reaches a plateau and stops.
More at Adjustments at High Altitude – Boundless